We definitely send notification (email) for certain critical alerts (suggest you install AES 7.1.7 to check the actual implementation). But there is room to improve, you may find this internal link helpful: US-85570 : Categorize AES alerts
Monitored node sends out health messages every two minutes that include the average HTTP response time. If it exceeds 10 seconds it would start sending out a critical alert email, if you have subscribed for critical alert emails.
Sample email message:
AES health alert observed by "PRODAESAPP01" : httpResponse status has changed to critical for cluster "DELTA_ONE" node "App02_Node01" : The current avg HTTP response time 10.92 exceeds the critical threshold limit 10 sec.